Zoom lens and imaging device having the same

Abstract

To provide a zoom lens that achieves both widening of field angle and downsizing and is capable of maintaining high optical performance at vibration insulating, and an imaging device having the zoom lens.SOLUTION: The zoom lens includes a first lens group having negative refractive power and a rear group including at least three lens groups and having positive refractive power on the whole, arranged in order from an object side to an image side, wherein an interval between the first lens group and the rear group changes in zooming. The rear group includes a sub-group that moves in a direction including a component in a direction perpendicular to an optical axis during image blur correction, and the first lens group includes three or more negative lenses arranged in order from the object side to the image side. At least two of the three or more negative lenses have their convex surfaces facing the object side, and at least one of these has its concave surface facing the object side. A distortion amount of the maximum image height during infinity focusing at a wide angle end, a focal distance of the first lens group, and a focal distance of the last lens group arranged on the most image side are appropriately set, respectively.SELECTED DRAWING: Figure 1

Description

[Technical field]

[0001] The present invention relates to a zoom lens, which is suitable for digital video cameras, digital still cameras, broadcast cameras, cameras for silver halide film, surveillance cameras, vehicle-mounted cameras, and the like. [Background technology]

[0002] Conventionally, as a means for correcting image blur, there are known a lens-shift type vibration isolation mechanism that shifts a part of the optical system in a direction perpendicular to the optical axis, and a sensor-shift type vibration isolation mechanism that shifts the image sensor. Patent Document 1 discloses a zoom lens equipped with a lens-shift type vibration isolation mechanism. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2019-215565 A Summary of the Invention [Problem to be solved by the invention]

[0004] In the zoom lens of Patent Document 1, when attempting to obtain a large amount of correction, the amount of decentering of the vibration reduction group becomes large, and when image blur is corrected, the image becomes blurred due to decentering aberration.

[0005] When using an ultra-wide-angle zoom lens with an angle of view exceeding 100°, a sensor-shift type vibration reduction mechanism is often used because a small shift amount can provide a large amount of correction. Since the amount of movement of the image point with respect to the change in the angle of incidence of light rays entering an optical system of the central projection method is not uniform on the imaging surface, in a zoom lens that suppresses distortion aberration using the central projection method, even if image blurring is corrected at the center of the imaging surface, a lot of image blurring remains around the imaging surface. If the projection method is made closer to an equidistant projection method with no difference in image blurring in order to suppress image blurring around the imaging surface, the image will be significantly distorted, so such a zoom lens is often used in conjunction with an imaging device having an electronic distortion correction function that corrects distortion aberration by image processing. However, if distortion aberration is excessively generated in the central projection method, the image quality around the imaging surface will deteriorate due to electronic distortion correction. Therefore, in order to achieve both image blurring correction and suppression of image quality deterioration around the imaging surface due to electronic distortion correction, it is necessary to appropriately set the distortion aberration in the central projection method.

[0006] In addition, a lens-shift type vibration isolation mechanism can suppress image blurring at the periphery of the image plane because the vibration isolation sensitivity (the ratio of the amount of image blur correction to the unit movement amount of the vibration isolation group) is higher at the periphery of the image plane than at the center of the image plane. Therefore, it is desirable to install a lens-shift type vibration isolation mechanism in an ultra-wide-angle zoom lens.

[0007] An object of the present invention is to provide a zoom lens that achieves both a wide angle of view and compactness, and that can maintain high optical performance even during vibration reduction, and an image pickup apparatus having the same. [Means for solving the problem]

[0008] A zoom lens according to one aspect of the present invention comprises a first lens group having negative refractive power, and a rear group including at least three lens groups having positive refractive power overall, arranged in that order from the object side to the image side, wherein the distance between the first lens group and the rear group changes during zooming, and the rear group includes a subgroup that moves in a direction including a component perpendicular to the optical axis during image blur correction, and the first lens group includes three or more negative lenses arranged in that order from the object side to the image side, and of the three or more negative lenses, at least two have a shape with a convex surface facing the object side and at least one has a shape with a concave surface facing the object side, whereby an amount of distortion at a maximum image height when focusing at infinity at the wide-angle end is Dist_w, a focal length of the first lens group is f1, and a focal length of the final lens group arranged closest to the image side is fLN, -20 <Dist_w<-8 -0.4 <f1 / fLN<0.7 The present invention is characterized in that the following conditional expression is satisfied: Effect of the Invention

[0009] According to the present invention, it is possible to provide a zoom lens that achieves both a wide angle of view and compactness, and is capable of maintaining high optical performance even during vibration reduction, and an imaging apparatus having the same. [Brief description of the drawings]

[0010] [Figure 1] 1 is a cross-sectional view of a zoom lens according to a first embodiment. [Diagram 2] 3A and 3B are longitudinal aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 1. [Diagram 3] 4A and 4B are lateral aberration diagrams of the zoom lens of Example 1 at the wide-angle end and at the telephoto end during image stabilization. [Figure 4] FIG. 11 is a cross-sectional view of a zoom lens according to a second embodiment. [Diagram 5] 13A and 13B are longitudinal aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 2. [Figure 6] 13A and 13B are lateral aberration diagrams of the zoom lens of Example 2 at the wide-angle end and at the telephoto end during image stabilization. [Figure 7] FIG. 11 is a cross-sectional view of a zoom lens according to a third embodiment. [Figure 8] 13A and 13B are longitudinal aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 3. [Figure 9] 13A and 13B are lateral aberration diagrams of the zoom lens of Example 3 at the wide-angle end and at the telephoto end during image stabilization. [Figure 10] FIG. 11 is a cross-sectional view of a zoom lens according to a fourth embodiment. [Figure 11] 13A and 13B are longitudinal aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 4. [Figure 12] 13A and 13B are lateral aberration diagrams of the zoom lens of Example 4 at the wide-angle end and the telephoto end during image stabilization. [Figure 13] FIG. 11 is a cross-sectional view of a zoom lens according to a fifth embodiment. [Figure 14] 13A and 13B are longitudinal aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 5. [Figure 15] 13A and 13B are lateral aberration diagrams of the zoom lens of Example 5 at the wide-angle end and at the telephoto end during image stabilization. [Figure 16] FIG. 13 is a cross-sectional view of a zoom lens according to a sixth embodiment. [Figure 17] 13A and 13B are longitudinal aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 6. [Figure 18] 13A and 13B are lateral aberration diagrams of the zoom lens of Example 6 at the wide-angle end and the telephoto end during image stabilization. [Figure 19] FIG. 13 is a cross-sectional view of a zoom lens according to a seventh embodiment. [Figure 20] 13A and 13B are longitudinal aberration diagrams at the wide-angle end and the telephoto end of the zoom lens of Example 7. [Figure 21] 13A and 13B are lateral aberration diagrams of the zoom lens of Example 7 at the wide-angle end and the telephoto end during image stabilization. [Figure 22] FIG. 1 is a schematic diagram of an imaging device. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described in detail with reference to the drawings. In each drawing, the same reference numerals are given to the same members, and duplicated explanations will be omitted.

[0012] 1, 4, 7, 10, 13, 16, and 19 are cross-sectional views of the zoom lens L0 of Examples 1 to 7 at the wide-angle end when focusing on infinity. The zoom lens L0 of each Example is used in imaging devices such as digital video cameras, digital still cameras, broadcast cameras, silver halide film cameras, surveillance cameras, and vehicle-mounted cameras. The zoom lens L0 of each Example can also be used as a projection lens for projectors and the like.

[0013] In each cross-sectional view, the left side is the object side (front) and the right side is the image side (rear). The zoom lens L0 of each embodiment is configured to have multiple lens groups. In this specification, a lens group is a group of lenses that move or stand still as a unit during zooming. That is, in the zoom lens L0 of each embodiment, the distance between adjacent lens groups changes during zooming. Note that the lens group may be configured of one lens, or multiple lenses. The lens group may also include elements other than the lens group (for example, an aperture stop).

[0014] The zoom lens L0 of each embodiment is composed of a first lens group L1 with negative refractive power and a rear group LR with positive refractive power overall, arranged in that order from the object side to the image side. The rear group LR includes all lens groups arranged closer to the image side than the first lens group L1. In the zoom lens L0 of each embodiment, the distance between the first lens group L1 and the rear group LR changes during zooming.

[0015] In each cross-sectional view, Li denotes the i-th lens group (i is a natural number) counted from the object side among the lens groups included in the zoom lens L0, and LN denotes the final lens group located closest to the image side.

[0016] Also, SP is an aperture stop. The aperture stop SP is provided on the object side of or inside the second lens group L2. FC is a secondary stop (auxiliary stop). IP is an image plane, and when the zoom lens L0 of each embodiment is used as the photographing optical system of a digital still camera or digital video camera, the imaging surface of a solid-state imaging element (photoelectric conversion element) such as a CCD sensor or CMOS sensor is disposed thereon. When the zoom lens L0 of each embodiment is used as the photographing optical system of a silver halide film camera, a photosensitive surface equivalent to the film surface is disposed on the image plane IP.

[0017] The arrows in the cross-sectional views indicate the movement direction of the lens group during zooming from the wide-angle end to the telephoto end, and the movement direction of the lens group during focusing from an object at infinity to a close object. In each embodiment, one lens group is moved as a whole during focusing, but the present invention is not limited to this. During focusing, only a part of the lens group may be moved, or the entire zoom lens L0 may be moved. Furthermore, during focusing, multiple lenses may be moved along different trajectories.

[0018] 2, 5, 8, 11, 14, 17, and 20 are longitudinal aberration diagrams of the zoom lens L0 of Examples 1 to 7, respectively. In each longitudinal aberration diagram, (A) is a longitudinal aberration diagram at the wide-angle end, and (B) is a longitudinal aberration diagram at the telephoto end. In the spherical aberration diagram, Fno is the F-number, and shows the amount of spherical aberration for the d-line (wavelength 587.6 nm) and the g-line (wavelength 435.8 nm). In the astigmatism diagram, M shows the amount of astigmatism in the meridional image plane, and S shows the amount of astigmatism in the sagittal image plane. In the distortion aberration diagram, the amount of distortion aberration for the d-line is shown. In the chromatic aberration diagram, the amount of chromatic aberration at the g-line is shown. ω is the half angle of view (°).

[0019] 3, 6, 9, 12, 15, 18, and 21 are diagrams showing lateral aberration of the zoom lens L0 of each embodiment when image stabilization is performed at 0.3°. In each diagram, (A) shows the lateral aberration at the wide-angle end, and (B) shows the lateral aberration at the telephoto end. The unit of each axis is mm. Y is the image height (mm) at which the lateral aberration diagram is evaluated.

[0020] Next, the characteristic configuration of the zoom lens L0 of each embodiment will be described.

[0021] The zoom lens L0 in each embodiment is a so-called negative lead type zoom lens in which the refractive power of the first lens unit L1 is negative. The negative lead type zoom lens is known as an effective configuration for making the zoom lens have a wider angle.

[0022] The rear group LR includes a subgroup (anti-vibration group) LIS that moves in a direction including a component perpendicular to the optical axis during image blur correction. This makes it possible to lower the height of off-axis light rays incident on the subgroup LIS, and suppress deterioration of optical performance during anti-vibration. In this specification, the subgroup refers to a group of lenses whose construction length (the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side of the subgroup) remains unchanged during zooming. The subgroup may be one lens group or a part of one lens group.

[0023] The first lens group L1 includes three or more negative lenses arranged in order from the object side to the image side, which makes it possible to ensure a sufficiently wide angle (for example, a field angle of 100° or more at the wide-angle end).

[0024] The zoom lens L0 of each embodiment satisfies the following conditional expressions (1) and (2).

[0025] -20 <Dist_w<-8 (1) -0.4 <f1 / fLN<0.7 (2) Here, Dist_w is the amount of distortion at the maximum image height when focusing on infinity at the wide-angle end, f1 is the focal length of the first lens group L1, and fLN is the focal length of the final lens group LN.

[0026] Conditional formula (1) specifies the amount of distortion at the maximum image height when focusing at infinity at the wide-angle end. The maximum image height is the distance from the optical axis to the image point that is furthest from the optical axis among the image points that can be photographed. If the amount of distortion becomes too large by exceeding the upper limit of conditional formula (1), the amount of distortion in the equidistant projection method becomes too large, resulting in significant degradation of image quality around the imaging surface during image blur correction. Also, even during lens shift vibration reduction, the amount of image blur correction around the imaging surface becomes insufficient. If the amount of distortion becomes too small by falling below the lower limit of conditional formula (1), it becomes difficult to suppress degradation of image quality around the imaging surface during electronic distortion correction.

[0027] Here, when the ideal image height in the central projection method is y and the real image height is yp, the distortion amount Dist_w [%] of an arbitrary image height at the wide-angle end is defined by the following formula.

[0028] Dist_w[%]=((yp-y) / y)×100 Further, the ideal image height y in the central projection method is defined by the following equation, where f is the focal length of the zoom lens L0 and θi is the half angle of view of the actual light ray at an arbitrary image height.

[0029] y=f tan θi Conditional formula (2) specifies the ratio of the focal length of the first lens group L1 to the focal length of the final lens group LN. By satisfying conditional formula (2), it is possible to achieve both compactness and high image quality. If the upper limit of conditional formula (2) is exceeded and the negative refractive power of the final lens group LN becomes too strong, it becomes difficult to achieve a retrofocus refractive power arrangement, and it becomes difficult to widen the angle of view while ensuring the back focus at the wide-angle end. If the lower limit of conditional formula (2) is exceeded and the positive refractive power of the final lens group LN becomes too strong, the retrofocus refractive power arrangement becomes strong, and the asymmetry of the refractive power arrangement of the zoom lens L0 becomes stronger, making it difficult to correct distortion at the wide-angle end. In addition, it becomes difficult to shorten the total lens length of the zoom lens L0 at the wide-angle end (the distance on the optical axis from the lens surface closest to the object to the image surface IP).

[0030] By having the above-mentioned configuration, the zoom lens L0 of each embodiment can achieve both a wide angle of view and compact size, and can maintain high optical performance even during vibration reduction.

[0031] It is preferable that the numerical ranges of the conditional expressions (1) and (2) be the numerical ranges of the following conditional expressions (1a) and (2a).

[0032] -19 <Dist_w<-9 (1a) -0.37 <f1 / fLN<0.60 (2a) It is further preferable that the numerical ranges of the conditional expressions (1) and (2) be the numerical ranges of the following conditional expressions (1b) and (2b).

[0033] -18 <Dist_w<-10 (1b) -0.34 <f1 / fLN<0.50 (2b) Next, conditions that the zoom lens L0 of each embodiment should preferably satisfy will be described. The zoom lens L0 of each embodiment should preferably satisfy one or more of the following conditional expressions (3) to (12).

[0034] 1.0<|fLIS / ft|<4.0 (3) 0.00≦dIS / dt<0.25 (4) 0.1 <dLIS / dR<10.0 (5) 30<νLIS<70 (6) -1.0<(r1+r2) / (r1-r2)<0.6 (7) -2.2 <f1 / skw<-0.9 (8) -2.2 <f1 / fw<-1.0 (9) -0.5 <fw / fLN<0.3 (10) -1.5 <Ymax_w / f1<-0.4 (11) Here, fLIS is the focal length of the subgroup LN. ft is the focal length of the zoom lens L0 at the telephoto end. dIS is the distance on the optical axis from the lens surface closest to the object of the rear group LR to the lens surface closest to the object of the subgroup LIS at the telephoto end. dt is the total lens length of the zoom lens L0 at the telephoto end. dLIS is the distance on the optical axis from the lens surface closest to the object of the subgroup LIS to the lens surface closest to the image. dR is the distance on the optical axis from the lens surface closest to the image of the subgroup LIS at the wide-angle end to the lens surface closest to the object of the lens group arranged adjacent to the subgroup LIS on the image side. νLIS is the Abbe number of the lens with the shortest focal length included in the subgroup LIS. r1 is the radius of curvature of the lens surface closest to the object of the subgroup LIS. r2 is the radius of curvature of the lens surface closest to the image of the subgroup LIS. skw is the back focus of the zoom lens L0 at the wide-angle end. fw is the focal length of the zoom lens L0 at the wide-angle end. Ymax_w is the maximum image height at the wide-angle end.

[0035] Conditional formula (3) specifies the refractive power of the subgroup LIS. By satisfying conditional formula (3), it is possible to achieve both a reduction in the lens outer diameter and suppression of aberration fluctuations during image stabilization. If the upper limit of conditional formula (3) is exceeded and the refractive power of the subgroup LIS becomes too weak, the amount of movement of the subgroup LIS during image stabilization becomes too large, making it difficult to reduce the lens outer diameter. If the refractive power of the subgroup LIS falls below the lower limit of conditional formula (3) and becomes too strong, it becomes difficult to suppress fluctuations in coma aberration and field curvature during image stabilization.

[0036] Conditional formula (4) specifies the distance on the optical axis from the lens surface of the rear group LR closest to the object to the lens surface of the partial group LIS closest to the object at the telephoto end. If the distance from the lens surface of the rear group LR closest to the object to the lens surface of the partial group LIS closest to the object becomes too long, exceeding the upper limit of conditional formula (4), it becomes difficult to suppress the fluctuation of coma aberration during image stabilization. If the distance from the lens surface of the rear group LR closest to the object to the lens surface of the partial group LIS closest to the object becomes too short, falling below the lower limit of conditional formula (4), it becomes difficult to appropriately position the drive unit that drives the partial group LIS and the drive unit that drives the aperture stop SP.

[0037] Conditional formula (5) defines the ratio of the thickness of the subgroup LIS to the spacing of the subsequent group LR. If the thickness of the subgroup LIS exceeds the upper limit of conditional formula (5) and becomes too thick, the subgroup LIS becomes heavy, the drive unit becomes large, and it becomes difficult to reduce the outer diameter of the lens. If the thickness of the subgroup LIS falls below the lower limit of conditional formula (5) and becomes too thin, it becomes difficult to appropriately set the radius of curvature of the subgroup LIS, and it becomes difficult to suppress fluctuations in coma aberration and field curvature during image stabilization.

[0038] Conditional formula (6) specifies the Abbe number of the lens with the shortest focal length included in the subgroup LIS. When the subgroup LIS has positive refractive power, it specifies the Abbe number of the positive lens, and when the subgroup LIS has negative refractive power, it specifies the Abbe number of the negative lens. If the Abbe number exceeds the upper limit of conditional formula (6) and becomes large, the refractive index becomes small, making it difficult to suppress fluctuations in coma aberration during image stabilization. If the Abbe number falls below the lower limit of conditional formula (6) and becomes small, it becomes difficult to suppress fluctuations in chromatic aberration of magnification during image stabilization.

[0039] Conditional formula (7) specifies the shape factor of the subgroup LIS. If the upper limit of conditional formula (7) is exceeded and the subgroup LIS has a meniscus shape with its concave surface facing the image side, it becomes difficult to suppress fluctuations in field curvature during image vibration reduction. If the lower limit of conditional formula (7) is exceeded and the subgroup LIS has a meniscus shape with its concave surface facing the object side, it becomes difficult to suppress fluctuations in coma aberration during image vibration reduction.

[0040] Conditional formula (8) defines the ratio of the back focus of the zoom lens L0 at the wide-angle end to the focal length of the first lens group L1. If the upper limit of conditional formula (8) is exceeded and the negative refractive power of the first lens group L1 becomes too strong, the asymmetry of the refractive power arrangement of the zoom lens L0 increases, making it difficult to correct distortion at the wide-angle end. If the lower limit of conditional formula (8) is exceeded and the negative refractive power of the first lens group L1 becomes too weak, it becomes difficult to achieve a wide angle of view exceeding 100° at the wide-angle end. In addition, the front lens diameter becomes large, and the lens outer diameter becomes large.

[0041] Conditional expression (9) defines the focal length of the first lens group L1. If the upper limit of conditional expression (9) is exceeded and the negative refractive power of the first lens group L1 becomes too strong, the asymmetry of the refractive power arrangement of the zoom lens L0 increases, making it difficult to correct distortion at the wide-angle end. If the lower limit of conditional expression (9) is exceeded and the refractive power of the first lens group L1 becomes too weak, it becomes difficult to achieve a wide angle of view exceeding 100° at the wide-angle end. In addition, the front lens diameter becomes large, and the lens outer diameter becomes large.

[0042] Conditional formula (10) specifies the focal length of the final lens group LN. If the upper limit of conditional formula (10) is exceeded and the positive refractive power of the final lens group LN becomes too strong, the retrofocus refractive power arrangement becomes strong, and the asymmetry of the refractive power arrangement of the zoom lens L0 becomes stronger, making it difficult to correct distortion at the wide-angle end. In addition, it becomes difficult to shorten the overall lens length at the wide-angle end. If the lower limit of conditional formula (10) is exceeded and the negative refractive power of the final lens group LN becomes too strong, it becomes difficult to achieve a retrofocus refractive power arrangement, making it difficult to widen the angle of view while ensuring the back focus at the wide-angle end.

[0043] Conditional expression (11) specifies the maximum image height that can be captured at the wide-angle end. By satisfying conditional expression (11), the zoom lens L0 can be made small and lightweight. If the maximum image height exceeds the upper limit and becomes too large, a wider range of light rays than the desired angle of view will be imaged on the imaging surface, causing the mechanical mechanism and optical system to become excessively large, making it difficult to make the zoom lens L0 small and lightweight. If the maximum image height falls below the lower limit and becomes too small, the angle of view will be narrower than the desired angle of view, which is undesirable.

[0044] It is preferable that the numerical ranges of the conditional expressions (3) to (11) be the numerical ranges of the following conditional expressions (3a) to (11a).

[0045] 1.1<|fLIS / ft|<3.5 (3a) 0.00≦dIS / dt<0.20 (4a) 0.2 <dLIS / dR<8.0 (5a) 32 <vLIS<68 (6a) -0.8<(r1+r2) / (r1-r2)<0.5 (7a) -2.1 <f1 / skw<-1.0 (8a) -2.1 <f1 / fw<-1.1 (9a) -0.40 <fw / fLN<0.25 (10a) -1.4 <Ymax_w / f1<-0.5 (11a) It is further preferable that the numerical ranges of the conditional expressions (3) to (11) be the numerical ranges of the following conditional expressions (3b) to (11b).

[0046] 1.2<|fLIS / ft|<3.0 (3b) 0.00≦dIS / dt<0.15 (4b) 0.3 <dLIS / dR<6.0 (5b) 34 <vLIS<66 (6b) -0.7<(r1+r2) / (r1-r2)<0.4 (7b) -2.0 <f1 / skw<-1.1 (8b) -2.0 <f1 / fw<-1.2 (9b) -0.30 <fw / fLN<0.20 (10b) -1.3 <Ymax_w / f1<-0.6 (11b) Next, the configuration that is preferably satisfied in the zoom lens L0 of each embodiment will be described.

[0047] It is preferable that the subgroup LIS includes a positive lens and a negative lens, which makes it possible to effectively suppress fluctuations in lateral chromatic aberration and field curvature during image stabilization.

[0048] The rear group LR is preferably disposed on the image side of the partial group LIS and includes two or more lens groups whose spacing changes during zooming, which makes it possible to achieve a sufficient zoom ratio (e.g., 2x) while ensuring a sufficiently wide angle (e.g., a field angle of 100° or more at the wide-angle end).

[0049] The rear group LR is preferably disposed on the image side of the partial group LIS and includes a focus group that moves during focusing. By disposing the vibration reduction group near the aperture and the focus group near the image plane, it is possible to suppress aberration fluctuations during vibration reduction and during focusing at the same time.

[0050] At the wide-angle end, among the distances between the lens groups included in the zoom lens L0, it is preferable that the distance between the first lens group L1 and the rear group LR be maximum. With this configuration, it is possible to increase the change in the distance between the first lens group L1 and the rear group LR during zooming, making it easy to ensure the desired zoom ratio.

[0051] It is preferable that the first lens group L1 includes a positive lens. With this configuration, chromatic aberration can be corrected within the first lens group L1, and fluctuations in chromatic aberration during zooming can be suppressed.

[0052] It is preferable that the zoom lens L0 has a storage unit that stores distortion correction data for correcting distortion. With such a configuration, it is possible to realize a reduction in the size of the zoom lens L0.

[0053] Next, the zoom lens L0 of each embodiment will be described in detail.

[0054] The zoom lens L0 of the first embodiment is composed of a first lens group L1 with negative refractive power and a rear group LR with negative refractive power as a whole, which are arranged in order from the object side to the image side. The rear group LR is composed of a second lens group L2 with positive refractive power, a third lens group L3 with negative refractive power, a fourth lens group L4 with negative refractive power, and a fifth lens group L5 with positive refractive power, which are arranged in order from the object side to the image side. A part of the second lens group L2 is a partial group LIS. The third lens group L3 is a focus group. The fifth lens group L5 is the final lens group LN. During zooming from the wide-angle end to the telephoto end, the first lens group L1 moves to the image side and then moves to the object side. The second lens group L2 moves to the object side while decreasing the distance between it and the first lens group L1. The third lens group L3 moves to the object side while increasing the distance between it and the second lens group L2. The fourth lens group L4 moves to the object side while decreasing the distance between it and the third lens group L3. The fifth lens group L5 moves toward the object side while increasing the distance between it and the fourth lens group L4, and then moves toward the image side. In addition, when focusing from an object at infinity to a close object, the third lens group L3 moves toward the image side.

[0055] The zoom lens L0 of the second embodiment is composed of a first lens group L1 with negative refractive power and a rear lens group LR with negative refractive power as a whole, which are arranged in order from the object side to the image side. The rear lens group LR is composed of a second lens group L2 with positive refractive power, a third lens group L3 with negative refractive power, a fourth lens group L4 with positive refractive power, a fifth lens group L5 with negative refractive power, and a sixth lens group L6 with positive refractive power, which are arranged in order from the object side to the image side. The third lens group L3 is a partial group LIS. The fifth lens group L5 is a focus group. The sixth lens group L6 is the final lens group LN. During zooming from the wide-angle end to the telephoto end, the first lens group L1 moves toward the image side. The second lens group L2 moves toward the object side while decreasing the distance between the first lens group L1 and the third lens group L3. The third lens group L3 moves toward the object side while decreasing the distance between the second lens group L2 and the third lens group L3. The fourth lens group L4 moves toward the object side while decreasing the distance between it and the third lens group L3. The fifth lens group L5 moves toward the object side while increasing the distance between it and the fourth lens group L4. The sixth lens group L6 moves toward the object side while increasing the distance between it and the fifth lens group L5. When focusing from an object at infinity to an object at a close distance, the fifth lens group L5 moves toward the image side.

[0056] The zoom lens L0 of the third embodiment is composed of a first lens group L1 with negative refractive power and a rear lens group LR with negative refractive power as a whole, which are arranged in order from the object side to the image side. The rear lens group LR is composed of a second lens group L2 with positive refractive power, a third lens group L3 with positive refractive power, a fourth lens group L4 with negative refractive power, a fifth lens group L5 with negative refractive power, and a sixth lens group L6 with positive refractive power, which are arranged in order from the object side to the image side. A part of the second lens group L2 is a partial group LIS. The fourth lens group L4 is a focus group. The sixth lens group L6 is the final lens group LN. During zooming from the wide-angle end to the telephoto end, the first lens group L1 moves to the image side and then moves to the object side. The second lens group L2 moves to the object side while decreasing the distance between it and the first lens group L1. The third lens group L3 moves to the object side while decreasing the distance between it and the second lens group L2. The fourth lens group L4 moves toward the object side while increasing the distance between it and the third lens group L3. The fifth lens group L5 moves toward the object side while decreasing the distance between it and the fourth lens group L4. The sixth lens group L6 does not move. Furthermore, when focusing from an object at infinity to an object at a close distance, the fourth lens group L4 moves toward the image side.

[0057] The zoom lens L0 of the fourth embodiment is composed of a first lens group L1 with negative refractive power and a rear lens group LR with negative refractive power as a whole, which are arranged in order from the object side to the image side. The rear lens group LR is composed of a second lens group L2 with positive refractive power, a third lens group L3 with negative refractive power, a fourth lens group L4 with positive refractive power, a fifth lens group L5 with negative refractive power, a sixth lens group L6 with negative refractive power, and a seventh lens group L7 with positive refractive power, which are arranged in order from the object side to the image side. The third lens group L3 is a partial group LIS. The fifth lens group L5 is a focus group. The seventh lens group L7 is a final lens group LN. During zooming from the wide-angle end to the telephoto end, the first lens group L1 moves to the image side and then moves to the object side. The second lens group L2 moves to the object side while decreasing the distance between it and the first lens group L1. The third lens group L3 moves to the object side while increasing the distance between it and the second lens group L2. The fourth lens group L4 moves toward the object side while decreasing the distance between it and the third lens group L3. The fifth lens group L5 moves toward the object side while increasing the distance between it and the fourth lens group L4. The sixth lens group L6 moves toward the object side while decreasing the distance between it and the fifth lens group L5. The seventh lens group L7 does not move. Furthermore, when focusing from an object at infinity to an object at a close distance, the fifth lens group L5 moves toward the image side.

[0058] The zoom lens L0 of the fifth embodiment is composed of a first lens group L1 with negative refractive power and a rear lens group LR with negative refractive power as a whole, which are arranged in order from the object side to the image side. The rear lens group LR is composed of a second lens group L2 with positive refractive power, a third lens group L3 with negative refractive power, a fourth lens group L4 with negative refractive power, and a fifth lens group L5 with positive refractive power, which are arranged in order from the object side to the image side. A part of the second lens group L2 is a partial group LIS. The third lens group L3 is a focus group. The fifth lens group L5 is the final lens group LN. During zooming from the wide-angle end to the telephoto end, the first lens group L1 moves to the image side and then moves to the object side. The second lens group L2 moves to the object side while decreasing the distance between it and the first lens group L1. The third lens group L3 moves to the object side while increasing the distance between it and the second lens group L2. The fourth lens group L4 moves to the object side while decreasing the distance between it and the third lens group L3. The fifth lens group L5 moves toward the image side while increasing the distance between it and the fourth lens group L4. Furthermore, during focusing from an object at infinity to an object at a close distance, the third lens group L3 moves toward the image side.

[0059] The zoom lens L0 of the sixth embodiment is composed of a first lens group L1 with negative refractive power and a rear lens group LR with negative refractive power as a whole, which are arranged in order from the object side to the image side. The rear lens group LR is composed of a second lens group L2 with positive refractive power, a third lens group L3 with positive refractive power, a fourth lens group L4 with negative refractive power, a fifth lens group L5 with negative refractive power, and a sixth lens group L6 with positive refractive power, which are arranged in order from the object side to the image side. A part of the second lens group L2 is a partial group LIS. The fourth lens group L4 is a focus group. The sixth lens group L6 is the final lens group LN. During zooming from the wide-angle end to the telephoto end, the first lens group L1 moves to the image side and then moves to the object side. The second lens group L2 moves to the object side while decreasing the distance between it and the first lens group L1. The third lens group L3 moves to the object side while decreasing the distance between it and the second lens group L2. The fourth lens group L4 moves toward the object side while increasing the distance between it and the third lens group L3. The fifth lens group L5 moves toward the object side while decreasing the distance between it and the fourth lens group L4. The sixth lens group L6 does not move. Furthermore, when focusing from an object at infinity to an object at a close distance, the fourth lens group L4 moves toward the image side.

[0060] The zoom lens of the seventh embodiment is composed of a first lens group L1 with negative refractive power and a rear group LR with negative refractive power as a whole, which are arranged in order from the object side to the image side. The rear group LR is composed of a second lens group L2 with positive refractive power, a third lens group L3 with negative refractive power, and a fourth lens group L4 with negative refractive power, which are arranged in order from the object side to the image side. A part of the second lens group L2 is a partial group LIS. The third lens group L3 is a focus group. The fourth lens group L4 is the final lens group LN. During zooming from the wide-angle end to the telephoto end, the first lens group L1 moves to the image side and then moves to the object side. The second lens group L2 moves to the object side while decreasing the distance between it and the first lens group L1. The third lens group L3 moves to the object side while increasing the distance between it and the second lens group L2. The fourth lens group L4 moves to the object side while decreasing the distance between it and the third lens group L3. Furthermore, during focusing from an object at infinity to a close object, the third lens unit L3 moves toward the image side.

[0061] Numerical examples 1 to 7 corresponding to the first to seventh embodiments, respectively, are shown below.

[0062] In the surface data of each numerical example, r represents the radius of curvature of each optical surface, and d (mm) represents the axial spacing (distance on the optical axis) between the mth surface and the (m+1)th surface. Here, m is the surface number counted from the light incident side. In addition, nd represents the refractive index of each optical member with respect to the d-line, and νd represents the Abbe number of the optical member. The Abbe number νd of a certain material is given by the following when the refractive indices at the Fraunhofer lines d-line (587.6 nm), F-line (486.1 nm), C-line (656.3 nm), and g-line (wavelength 435.8 nm) are Nd, NF, and NC, respectively: νd=(Nd-1) / (NF-NC) It is expressed as:

[0063] In each numerical example, d, focal length (mm), F-number, and half angle of view (degrees) are all values ​​when the zoom lens L0 of each example is focused on an object at infinity. "Back focus" is the distance on the optical axis from the final lens surface (the lens surface closest to the image) to the paraxial image surface expressed as an air-equivalent length. "Total lens length" is the distance on the optical axis from the foreground (the lens surface closest to the object) of the zoom lens L0 to the final surface plus the back focus. The term "lens group" is not limited to cases where the lens group is composed of multiple lenses, but also includes cases where the lens group is composed of a single lens.

[0064] If the optical surface is aspheric, a * symbol is added to the right of the surface number. The aspheric shape is expressed as follows, where X is the displacement from the apex of the surface in the optical axis direction, h is the height from the optical axis in the direction perpendicular to the optical axis, R is the paraxial radius of curvature, K is the conic constant, and A4, A6, A8, A10, and A12 are the aspheric coefficients of each order: X = (h 2 / R) / [1+{1-(1+K)(h / R) 2} 1 / 2 +A4×h 4 +A6×h 6 +A8×h 8 +A10×h 10 +A12×h 12 In addition, "e±XX" in each aspheric coefficient is "×10± XX " It means. [Numerical Example 1] Unit: mm Surface Data Surface number rd nd νd Effective diameter 1 51.172 2.10 1.76385 48.5 60.00 2 22.116 5.35 41.92 3* 43.332 2.60 1.58313 59.4 41.25 4* 20.040 7.86 35.56 5 46.620 1.30 1.49700 81.5 35.20 6 20.811 8.63 30.19 7 -72.638 1.20 1.43875 94.7 29.72 8 28.416 3.02 27.38 9 31.708 4.25 1.72047 34.7 27.20 10 299.251 (variable) 26.57 11 (Aperture) ∞ 0.50 15.47 12 20.518 0.90 1.90043 37.4 16.09 13 14.081 5.42 1.51633 64.1 15.68 14 -41.681 1.39 15.71 15 -45.264 0.70 1.79952 42.2 15.44 16 17.644 2.65 2.00069 25.5 15.61 17 53.947 1.00 15.54 18 (auxiliary aperture) ∞ 1.25 15.63 19 18.253 0.80 1.95375 32.3 16.23 20 12.998 7.21 1.49700 81.5 15.66 21 -21.295 0.80 1.72916 54.7 15.48 22 45.323 0.15 15.64 23 19.970 5.19 1.43875 94.7 17.39 24 -54.434 0.15 18.22 25* 29.740 4.95 1.49700 81.5 18.94 26* -37.767 (variable) 19.14 27 50.182 0.75 1.72916 54.7 18.86 28 26.486 (variable) 18.54 29 -18.815 1.50 1.85400 40.4 19.72 30* -37.763 (variable) 21.83 31 -568.191 6.05 1.49700 81.5 36.04 32 -38.524 (variable) 37.01 Image plane ∞ Aspheric Data 3rd page K = 0.00000e+000 A 4= 7.52315e-005 A 6=-2.85004e-007 A 8= 8.08696e-010 A10=-1.62370e-012 A12= 2.19074e-015 A14=-1.39196e-018 Side 4 K =-7.00172e-001 A 4= 8.26202e-005 A 6=-2.36130e-007 A 8=-1.14795e-010 A10= 2.29302e-012 A12=-5.42273e-015 A14= 3.67687e-018 Page 25 K = 0.00000e+000 A 4=-4.19009e-005 A 6=-1.88923e-007 A 8= 2.54663e-009 A10=-2.45675e-011 A12= 1.85699e-013 Page 26 K = 0.00000e+000 A 4=-3.92596e-006 A 6=-2.00765e-007 A 8= 4.34769e-009 A10=-4.17031e-011 A12= 2.70334e-013 Page 30 K = 0.00000e+000 A 4= 3.55737e-005 A 6= 8.04633e-008 A 8=-5.06048e-011 A10=-1.92129e-012 A12= 1.00728e-014 Various data Zoom ratio 2.06 Wide Angle Mid-Telephoto Focal length 11.33 17.56 23.30 F-number 4.08 4.08 4.12 Half angle of view (degrees) 59.63 50.70 42.88 Image height 19.33 21.64 21.64 Lens length 135.40 127.26 130.90 BF 13.63 16.01 14.26 d10 31.08 13.08 6.86 d26 1.40 2.76 3.05 d28 10.82 9.46 9.16 d30 0.80 8.28 19.88 d32 13.63 16.01 14.26 Zoom lens group data Group starting plane focal length 1 1 -19.57 2 11 24.55 3 27 -77.97 4 29 -45.57 5 31 82.84 [Numerical Example 2] Unit: mm Surface Data Surface number rd nd νd Effective diameter 1 40.613 1.70 1.76385 48.5 51.00 2 19.325 5.42 36.63 3* 31.250 2.30 1.58313 59.4 35.85 4* 17.371 9.00 30.81 5 169.823 1.30 1.49700 81.5 30.26 6 27.182 6.81 26.85 7 -204.838 1.20 1.43875 94.7 24.92 8 26.012 3.14 1.72047 34.7 23.15 9 72.443 (variable) 22.50 10 31.749 2.47 1.54814 45.8 17.19 11 ∞ 0.50 17.35 12 (Aperture) ∞ 0.50 17.44 13 31.532 0.90 1.81554 44.4 17.78 14 14.990 5.80 1.51823 58.9 17.39 15 -58.790 (variable) 17.59 16 -47.567 0.70 1.72047 34.7 17.56 17 45.836 1.70 2.00069 25.5 17.89 18 176.965 2.00 17.96 19 (auxiliary aperture) ∞ (variable) 18.37 20 36.570 0.90 1.83481 42.7 19.05 21 17.537 5.37 1.43875 94.7 19.41 22 169.591 0.20 21.16 23 29.382 8.39 1.43875 94.7 23.63 24 -39.782 0.20 24.89 25* 59.282 9.17 1.49700 81.5 25.50 26* -31.136 (variable) 25.39 27 -91.656 1.50 2.00069 25.5 23.92 28 -57.835 0.75 1.72047 34.7 23.84 29 43.358 (variable) 23.25 30* -27.441 1.60 1.85400 40.4 23.53 31* -60.934 0.20 25.65 32 178.490 5.04 1.49700 81.5 27.62 33 -37.343 (variable) 28.73 Image plane ∞ Aspheric Data 3rd page K = 0.00000e+000 A 4= 6.49432e-005 A 6=-2.09847e-007 A 8= 3.22034e-010 A10=-3.56124e-014 A12=-2.65892e-016 A14=-2.11568e-019 Side 4 K =-5.81434e-001 A 4= 7.42938e-005 A 6=-8.59222e-008 A 8=-1.56177e-009 A10= 9.19947e-012 A12=-2.30787e-014 A14= 1.96904e-017 Page 25 K = 0.00000e+000 A 4=-1.13378e-005 A 6=-4.96476e-009 A 8= 3.96013e-011 A10= 5.02938e-013 A12= 1.73732e-015 Page 26 K = 0.00000e+000 A 4=-6.09923e-006 A 6= 1.18821e-008 A 8= 4.84539e-011 A10=-6.24432e-014 A12= 4.33687e-015 Page 30 K = 0.00000e+000 A 4=-6.59258e-005 A 6= 7.46300e-007 A 8=-5.93573e-009 A10= 2.94143e-011 A12=-6.27604e-014 Page 31 K = 0.00000e+000 A 4=-2.90274e-005 A 6= 6.29498e-007 A 8=-3.79841e-009 A10= 1.47494e-011 A12=-2.52922e-014 Various data Zoom ratio 1.89 Wide Angle Mid-Telephoto Focal length 12.36 17.28 23.30 F-number 2.91 2.91 2.91 Half angle of view (degrees) 57.41 51.25 42.88 Image height 19.33 21.64 21.64 Lens length 130.51 122.33 119.64 BF 13.43 18.88 24.55 d 9 22.59 9.36 1.00 d15 1.81 1.40 1.40 d19 5.47 3.28 1.30 d26 1.40 3.02 5.40 d29 7.03 7.60 7.20 d33 13.43 18.88 24.55 Zoom lens group data Group starting plane focal length 1 1 -16.25 2 10 32.38 3 16 -67.90 4 20 23.86 5 27 -43.80 6 30 2124.22 [Numerical Example 3] Unit: mm Surface Data Surface number rd nd νd Effective diameter 1 53.599 1.40 1.77250 49.6 43.82 2 18.113 5.22 32.21 3* 22.075 2.20 1.58313 59.4 31.65 4* 10.628 10.87 26.46 5 -44.745 1.00 1.49700 81.5 26.19 6 57.018 0.20 25.97 7 34.464 5.00 1.83400 37.2 26.18 8 -232.206 (variable) 25.60 9 (Aperture) ∞ 0.30 18.03 10 28.190 0.90 1.95375 32.3 18.71 11 16.928 4.39 1.63980 34.5 18.37 12 92.174 0.15 18.46 13 22.781 0.90 1.91082 35.3 18.81 14 13.865 7.08 1.51633 64.1 18.09 15 -77.716 1.33 18.16 16 -101.166 0.70 1.72047 34.7 18.03 17 22.540 2.37 2.00069 25.5 18.09 18 52.661 (variable) 17.96 19 27.758 0.90 1.80400 46.5 18.26 20 13.290 6.78 1.49700 81.5 17.64 21 -85.129 0.20 17.86 22* 31.208 6.99 1.49700 81.5 19.27 23* -21.124 (variable) 20.01 24 97.737 0.75 1.80400 46.5 19.32 25 22.020 (variable) 18.89 26* -83.892 1.60 1.85400 40.4 21.10 27* 1997.530 (variable) 22.21 28 -426.907 5.12 1.48749 70.2 38.12 29 -49.575 14.99 38.85 Image plane ∞ Aspheric Data 3rd page K = 0.00000e+000 A 4=-4.03233e-005 A 6= 2.84310e-007 A 8=-1.85419e-009 A10= 6.48125e-012 A12=-1.22378e-014 A14= 9.28892e-018 Side 4 K =-5.60601e-001 A 4=-6.16452e-005 A 6= 2.38219e-007 A 8=-1.71089e-009 A10=-6.46493e-012 A12= 6.50194e-014 A14=-1.76965e-016 Page 22 K = 0.00000e+000 A 4=-1.67837e-005 A 6=-3.64843e-008 A 8= 1.07618e-009 A10=-1.24350e-011 A12= 7.09601e-014 Page 23 K = 0.00000e+000 A 4= 1.93177e-005 A 6=-1.27575e-007 A 8= 6.12378e-010 A10=-8.15372e-012 A12= 4.33482e-014 Page 26 K = 0.00000e+000 A 4= 2.55101e-005 A 6=-2.64846e-007 A 8=-4.54960e-010 A10= 8.83199e-012 A12=-3.33076e-014 Page 27 K = 0.00000e+000 A 4= 3.69079e-005 A 6=-2.56285e-007 A 8= 4.52183e-010 A10= 1.47250e-012 A12=-6.14678e-015 Various data Zoom ratio 2.35 Wide Angle Mid-Telephoto Focal length 14.42 24.42 33.95 F-number 4.08 4.08 4.12 Half angle of view (degrees) 53.26 41.34 32.50 Image height 19.32 21.64 21.64 Lens length 125.87 118.34 125.87 BF 14.99 14.99 14.99 d 8 27.76 8.00 2.38 d18 4.14 2.93 1.30 d23 1.40 2.29 1.88 d25 7.46 6.57 6.97 d27 3.78 17.21 32.00 Zoom lens group data Group starting plane focal length 1 1 -22.94 2 9 62.86 3 19 21.50 4 24 -35.51 5 26 -94.24 6 28 114.54 [Numerical Example 4] Unit: mm Surface Data Surface number rd nd νd Effective diameter 1 69.215 1.70 1.76385 48.5 50.85 2 21.428 5.17 37.62 3* 31.249 2.30 1.58313 59.4 37.18 4* 15.909 12.89 32.33 5 -42.876 1.00 1.43875 94.7 31.99 6 106.477 0.20 31.70 7 45.553 4.49 1.83400 37.2 31.79 8 -634.660 (variable) 31.36 9 (Aperture) ∞ (Variable) 23.60 10 52.261 2.46 1.72916 54.7 26.10 11 263.265 0.15 26.10 12 31.910 0.90 1.95375 32.3 26.30 13 17.077 8.89 1.58267 46.4 24.93 14 -117.291 (variable) 24.86 15 -91.733 0.70 1.72047 34.7 24.27 16 27.559 2.96 2.00069 25.5 24.34 17 64.329 2.00 24.19 18 (auxiliary aperture) ∞ (variable) 24.31 19 32.406 0.90 1.83481 42.7 24.83 20 17.852 8.12 1.43875 94.7 23.93 21 -123.183 0.20 24.22 22* 33.004 9.54 1.49700 81.5 26.54 23* -23.827 (variable) 27.20 24 4131.745 2.01 2.00069 25.5 25.45 25 -88.248 0.75 1.72047 34.7 25.27 26 31.864 (variable) 24.27 27* -166.689 1.60 1.85400 40.4 24.90 28* 82.150 (variable) 25.59 29 595.501 5.92 1.49700 81.5 39.14 30 -50.768 15.11 39.80 Image plane ∞ Aspheric Data 3rd page K = 0.00000e+000 A 4= 1.41959e-005 A 6=-7.81904e-008 A 8= 3.46364e-010 A10=-1.01509e-012 A12= 1.45953e-015 A14=-7.30050e-019 Side 4 K =-6.36442e-001 A 4= 1.55368e-005 A 6=-1.12080e-007 A 8= 5.29838e-010 A10=-1.99889e-012 A12= 2.59583e-015 A14=-2.64013e-019 Page 22 K = 0.00000e+000 A 4=-6.99798e-006 A 6=-1.13680e-008 A 8= 1.53877e-011 A10=-1.10382e-013 A12=-4.97644e-016 Page 23 K = 0.00000e+000 A 4= 2.44559e-005 A 6=-8.82874e-008 A 8= 1.95669e-010 A10=-1.85265e-013 A12=-1.18827e-015 Page 27 K = 0.00000e+000 A 4= 5.05507e-005 A 6=-7.34842e-007 A 8= 4.77038e-009 A10=-1.90408e-011 A12= 3.62227e-014 Page 28 K = 0.00000e+000 A 4= 5.77402e-005 A 6=-6.55664e-007 A 8= 4.27445e-009 A10=-1.57305e-011 A12= 2.69924e-014 Various data Zoom ratio 2.20 Wide Angle Mid-Telephoto Focal length 15.45 25.03 33.95 F-number 2.91 2.91 2.91 Half angle of view (degrees) 51.37 40.70 32.51 Image height 19.33 21.64 21.64 Lens length 149.62 134.58 135.96 BF 15.11 15.11 15.11 d 8 38.59 12.29 2.42 d 9 0.50 3.59 4.63 d14 1.64 3.26 3.73 d18 8.30 3.20 1.30 d23 1.40 1.44 2.33 d26 6.53 8.68 6.05 d28 2.71 12.16 25.54 Zoom lens group data Group starting plane focal length 1 1 -28.99 2 9 ∞ 3 10 41.93 4 15 -75.73 5 19 25.63 6 24 -52.21 7 27 -64.25 8 29 94.41 [Numerical Example 5] Unit: mm Surface Data Surface number rd nd νd Effective diameter 1 48.538 2.10 1.76385 48.5 60.00 2 21.514 6.80 41.40 3* 41.518 2.60 1.58313 59.4 40.59 4* 19.615 11.68 34.73 5 -272.695 1.30 1.49700 81.5 34.04 6 37.773 3.45 30.53 7 -13097.059 1.20 1.43875 94.7 30.39 8 26.973 3.42 28.26 9 32.744 4.40 1.72047 34.7 28.06 10 377.895 (variable) 27.42 11 (Aperture) ∞ 0.50 14.70 12 22.168 0.90 1.88300 40.8 15.20 13 13.223 6.36 1.51633 64.1 14.83 14 -23.367 1.60 15.03 15 -20.976 0.70 1.83481 42.7 14.66 16 23.672 2.79 2.00069 25.5 15.34 17 -426.850 1.00 15.52 18 (auxiliary aperture) ∞ 1.95 15.76 19 28.067 0.80 2.05090 26.9 16.47 20 18.874 4.30 1.49700 81.5 16.18 21 -68.734 0.80 1.75500 52.3 16.31 22 41.203 0.15 16.50 23 23.795 5.71 1.43875 94.7 17.89 24 -30.878 0.15 19.00 25* 26.669 6.09 1.49700 81.5 20.24 26 -31.980 (variable) 20.40 27 43.537 0.75 1.72916 54.7 19.36 28 23.468 (variable) 18.81 29 -22.555 1.50 1.85400 40.4 19.05 30* -92.996 (variable) 20.61 31 167.684 5.58 1.49700 81.5 37.93 32 -64.072 (variable) 38.64 Image plane ∞ Aspheric Data 3rd page K = 0.00000e+000 A 4= 6.47302e-005 A 6=-2.29202e-007 A 8= 5.86104e-010 A10=-1.05964e-012 A12= 1.37744e-015 A14=-8.86881e-019 Side 4 K =-7.50843e-001 A 4= 7.46936e-005 A 6=-1.82700e-007 A 8=-2.68916e-010 A10= 2.54737e-012 A12=-5.55262e-015 A14= 3.33412e-018 Page 25 K = 0.00000e+000 A 4=-2.23064e-005 A 6=-6.28235e-008 A 8= 7.24431e-011 A10=-1.42742e-012 A12=-7.58488e-016 Page 30 K = 0.00000e+000 A 4= 3.94581e-005 A 6= 6.47504e-008 A 8=-2.02428e-010 A10= 4.29810e-014 A12= 3.69126e-015 Various data Zoom ratio 2.06 Wide Angle Mid-Telephoto Focal length 11.33 17.14 23.30 F-number 4.08 4.08 4.12 Half angle of view (degrees) 50.56 47.28 32.77 Image height 18.57 21.64 21.64 Lens length 137.09 129.80 130.30 BF 14.83 12.87 11.38 d10 31.31 14.87 6.22 d26 1.40 2.08 2.59 d28 9.65 8.97 8.46 d30 1.34 12.44 23.09 d32 14.83 12.87 11.38 Zoom lens group data Group starting plane focal length 1 1 -21.13 2 11 22.34 3 27 -70.94 4 29 -35.21 May 31 94.03 [Numerical Example 6] Unit: mm Surface Data Surface number rd nd νd Effective diameter 1 50.865 1.40 1.77250 49.6 42.93 2 17.863 7.25 31.67 3* 46.917 2.20 1.58313 59.4 30.93 4* 14.743 9.13 26.03 5 -53.512 1.00 1.49700 81.5 25.74 6 62.328 0.20 25.62 7 33.031 4.22 1.83400 37.2 25.87 8 -1410.574 (variable) 25.42 9 (Aperture) ∞ 0.30 17.61 10 30.753 0.90 1.95375 32.3 18.21 11 14.405 5.01 1.76200 40.1 17.88 12 178.071 1.00 17.95 13 28.952 0.90 1.72916 54.7 18.24 14 14.470 6.76 1.51633 64.1 17.75 15 -34.922 1.48 17.69 16 -34.130 0.70 1.55963 61.2 17.22 17 75.243 (variable) 17.21 18 37.725 0.90 1.80400 46.5 17.53 19 15.470 4.31 1.49700 81.5 17.17 20 110.900 0.15 17.36 21 26.976 4.77 1.49700 81.5 18.66 22 -40.410 0.15 19.20 23* 217.132 4.72 1.49700 81.5 19.39 24* -22.828 (variable) 19.86 25 -76007.456 0.75 1.80400 46.5 18.82 26 20.698 (variable) 18.48 27* -170.981 1.60 1.85400 40.4 21.99 28* 998.468 (variable) 22.94 29 2090.313 5.34 1.49700 81.5 38.25 30 -51.796 14.02 38.93 Image plane ∞ Aspheric Data 3rd page K = 0.00000e+000 A 4= 4.47960e-005 A 6=-3.48481e-007 A 8= 1.44040e-009 A10=-3.42659e-012 A12= 4.42059e-015 A14=-2.38393e-018 Side 4 K =-6.48193e-001 A 4= 5.35870e-005 A 6=-3.21360e-007 A 8=-3.48686e-010 A10= 1.17717e-011 A12=-5.28294e-014 A14= 7.55482e-017 Page 23 K = 0.00000e+000 A 4=-4.71833e-005 A 6=-8.44077e-008 A 8= 1.47111e-009 A10=-1.06774e-011 A12= 7.11865e-014 Page 24 K = 0.00000e+000 A 4=-7.69334e-006 A 6=-6.90014e-008 A 8= 1.57448e-009 A10=-1.47829e-011 A12= 8.11251e-014 Page 27 K = 0.00000e+000 A 4= 1.74890e-006 A 6=-3.81796e-009 A 8= 1.07601e-009 A10=-1.19626e-011 A12= 2.22566e-014 Page 28 K = 0.00000e+000 A 4= 9.96899e-006 A 6=-2.31241e-008 A 8= 1.03976e-009 A10=-1.09841e-011 A12= 2.47861e-014 Various data Zoom ratio 2.35 Wide Angle Mid-Telephoto Focal length 14.42 23.99 33.95 F-number 4.08 4.08 4.12 Half angle of view (degrees) 46.13 32.01 23.84 Image height 17.92 21.64 21.64 Lens length 125.86 115.15 121.59 BF 14.02 14.02 14.02 d 8 29.65 8.75 2.71 d17 5.30 4.07 2.19 d24 2.53 3.95 3.78 d26 7.71 6.29 6.46 d28 1.50 12.92 27.28 Zoom lens group data Group starting plane focal length 1 1 -22.76 2 9 55.69 3 18 21.12 4 25 -25.74 5 27 -170.83 6 29 101.78 [Numerical Example 7] Unit: mm Surface Data Surface number rd nd νd Effective diameter 1 45.081 2.10 1.76385 48.5 60.00 2 20.763 7.83 40.66 3* 39.376 2.60 1.58313 59.4 39.57 4* 19.086 12.09 34.05 5 -149.535 1.30 1.49700 81.5 33.35 6 42.685 3.55 30.11 7 -195.828 1.20 1.43875 94.7 29.98 8 27.111 1.08 27.96 9 34.838 4.66 1.72047 34.7 27.96 10 -508.780 (variable) 27.40 11 (Aperture) ∞ 0.50 13.28 12 22.100 0.90 1.88300 40.8 13.77 13 13.090 5.48 1.51633 64.1 13.51 14 -22.254 1.47 13.77 15 -21.928 0.70 1.83481 42.7 13.50 16 20.583 3.00 2.00069 25.5 14.08 17 -124.353 1.00 14.26 18 (auxiliary aperture) ∞ 2.22 14.40 19 28.757 0.80 2.05090 26.9 14.77 20 16.081 6.47 1.49700 81.5 14.44 21 -17.564 0.80 1.75500 52.3 15.27 22 167.455 0.15 16.78 23 29.244 5.87 1.43875 94.7 18.47 24 -25.744 0.15 19.61 25* 31.191 6.27 1.49700 81.5 20.72 26 -27.179 (variable) 20.92 27 29.696 0.75 1.72916 54.7 19.29 28 17.581 (variable) 18.46 29 -23.901 1.50 1.85400 40.4 18.65 30* 280.595 0.26 20.33 31 36.229 2.49 1.72825 28.5 22.47 32 118.225 (variable) 22.96 Image plane ∞ Aspheric Data 3rd page K = 0.00000e+000 A 4= 7.28829e-005 A 6=-3.12387e-007 A 8= 1.01671e-009 A10=-2.11222e-012 A12= 2.79184e-015 A14=-1.84122e-018 Side 4 K =-5.56940e-001 A 4= 8.13645e-005 A 6=-2.68703e-007 A 8=-1.48487e-010 A10= 4.94390e-012 A12=-1.70106e-014 A14= 1.68710e-017 Page 25 K = 0.00000e+000 A 4=-2.30258e-005 A 6=-6.54896e-008 A 8= 1.46618e-010 A10=-1.94958e-012 A12= 6.26213e-015 Page 30 K = 0.00000e+000 A 4= 4.62125e-005 A 6= 1.37240e-008 A 8= 4.45799e-010 A10=-4.84100e-012 A12= 1.52924e-014 Various data Zoom ratio 2.06 Wide Angle Mid-Telephoto Focal length 11.33 16.77 23.30 F-number 4.08 4.08 4.12 Half angle of view (degrees) 52.93 41.82 32.77 Image height 18.57 21.64 21.64 Lens length 135.25 125.30 120.88 BF 16.69 22.62 28.39 d10 31.65 14.80 3.48 d26 1.40 1.53 2.50 d28 8.34 9.17 9.32 d32 16.69 22.62 28.39 Zoom lens group data Group starting plane focal length 1 1 -19.40 2 11 21.92 3 27 -60.68 4 29 -40.75 Various values ​​in each numerical example are summarized in Table 1 below.

[0065] [Table 1]

[0066] [Imaging device] Next, an embodiment of a digital still camera (imaging device) using the zoom lens L0 of each embodiment as an imaging optical system will be described with reference to Fig. 22. In Fig. 22, 10 denotes a camera body, and 11 denotes an imaging optical system constituted by any of the zoom lenses L0 described in the first to seventh embodiments. 12 denotes a solid-state imaging element (photoelectric conversion element) such as a CCD sensor or a CMOS sensor that is built into the camera body and receives an optical image formed by the imaging optical system 11 and photoelectrically converts it. The camera body 10 may be a so-called single-lens reflex camera having a quick-turn mirror, or a so-called mirrorless camera having no quick-turn mirror.

[0067] In this way, by applying the zoom lens L0 of each embodiment to an imaging device such as a digital still camera, it is possible to obtain an imaging device with a small lens.

[0068] Although the preferred embodiments and examples of the present invention have been described above, the present invention is not limited to these embodiments and examples, and various combinations, modifications, and changes are possible within the scope of the gist of the present invention. [Explanation of symbols]

[0069] L0 Zoom Lens L1 First lens group LR rear group LIS subgroup LN final lens group

Claims

1. A zoom lens comprising a first lens group having negative refractive power and a rear group including at least three lens groups and having positive refractive power as a whole, the first lens group and the rear group being arranged in this order from an object side to an image side, the distance between the first lens group and the rear group being changed during zooming, the rear group includes a subgroup that moves in a direction including a component perpendicular to an optical axis during image blur correction, the first lens group includes three or more negative lenses arranged in order from the object side to the image side, Among the three or more negative lenses, at least two have a convex surface facing the object side, and at least one has a concave surface facing the object side, When the amount of distortion at the maximum image height when focusing on infinity at the wide-angle end is Dist_w, the focal length of the first lens group is f1, and the focal length of the final lens group disposed closest to the image side is fLN, -20<Dist_w<-8 -0.4<f1 / fLN<0.7 A zoom lens characterized by satisfying the following conditional expressions:

2. When the focal length of the subgroup is f and the focal length of the zoom lens at the telephoto end is ft, 1.0<|fLIS / ft|<4.0 2. The zoom lens according to claim 1, wherein the following condition is satisfied:

3. Let dIS be the distance on the optical axis from the lens surface of the rear group closest to the object side to the lens surface of the sub group closest to the object side at the telephoto end, and dt be the total lens length of the zoom lens at the telephoto end. 0.00≦dIS / dt<0.25 3. The zoom lens according to claim 1, wherein the following condition is satisfied:

4. When the distance on the optical axis from the lens surface closest to the object side to the lens surface closest to the image side of the subgroup is dLIS, and the distance on the optical axis from the lens surface closest to the image side of the subgroup at the wide-angle end to the lens surface closest to the object side of the lens group arranged adjacent to the subgroup on the image side is dR, 0.1<dLIS / dR<10.0 4. The zoom lens according to claim 1, which satisfies the following condition:

5. When the Abbe number of the lens with the shortest focal length included in the subgroup is ν, 30<νLIS<70 5. The zoom lens according to claim 1, which satisfies the following condition:

6. When the radius of curvature of the lens surface of the subgroup closest to the object side is r1 and the radius of curvature of the lens surface of the subgroup closest to the image side is r2, -1.0<(r1+r2) / (r1-r2)<0.6 6. The zoom lens according to claim 1, which satisfies the following condition:

7. When the back focus of the zoom lens at the wide-angle end is skw, -2.2<f1 / skw<-0.9 7. The zoom lens according to claim 1, which satisfies the following condition:

8. When the focal length of the zoom lens at the wide-angle end is fw, -2.2<f1 / fw<-1.0 8. The zoom lens according to claim 1, which satisfies the following condition:

9. When the focal length of the zoom lens at the wide-angle end is fw, -0.5<fw / fLN<0.3 9. The zoom lens according to claim 1, which satisfies the following condition:

10. When the maximum image height at the wide-angle end is Ymax_w, -1.5<Ymax_w / f1<-0.5 10. The zoom lens according to claim 1, which satisfies the following condition:

11. 11. The zoom lens according to claim 1, wherein the subgroup includes a positive lens and a negative lens.

12. 12. The zoom lens according to claim 1, wherein the rear group includes two or more lens groups that are arranged on the image side of the subgroup and whose spacing changes during zooming.

13. 13. The zoom lens according to claim 1, wherein the rear group has a focus group that is disposed on the image side of the partial group and moves during focusing.

14. 14. The zoom lens according to claim 1, wherein, at a wide-angle end, among the distances between the lens groups included in the zoom lens, the distance between the first lens group and the rear lens group is maximum.

15. 15. The zoom lens according to claim 1, wherein the first lens group includes a positive lens.

16. 16. The zoom lens according to claim 1, further comprising a storage unit for storing distortion correction data for correcting distortion aberration.

17. 17. The zoom lens according to claim 1, wherein the rear group consists of, arranged in order from the object side to the image side, a second lens group having positive refractive power, a third lens group having negative refractive power, a fourth lens group having negative refractive power, and a fifth lens group having positive refractive power.

18. 17. The zoom lens according to claim 1, wherein the rear group consists of, arranged in order from the object side to the image side, a second lens group having positive refractive power, a third lens group having negative refractive power, a fourth lens group having positive refractive power, a fifth lens group having negative refractive power, and a sixth lens group having positive refractive power.

19. 17. The zoom lens according to claim 1, wherein the rear group consists of, arranged in order from the object side to the image side, a second lens group having positive refractive power, a third lens group having positive refractive power, a fourth lens group having negative refractive power, a fifth lens group having negative refractive power, and a sixth lens group having positive refractive power.

20. 17. The zoom lens according to claim 1, wherein the rear group consists of, arranged in order from the object side to the image side, a second lens group having positive refractive power, a third lens group having negative refractive power, a fourth lens group having positive refractive power, a fifth lens group having negative refractive power, a sixth lens group having negative refractive power, and a seventh lens group having positive refractive power.

21. 17. The zoom lens according to claim 1, wherein the rear group consists of, arranged in order from the object side to the image side, a second lens group having positive refractive power, a third lens group having negative refractive power, and a fourth lens group having negative refractive power.

22. 22. An imaging apparatus comprising: the zoom lens according to claim 1; and an imaging element that receives an image formed by the zoom lens.

Images